| 1 | // Copyright 2013 The Chromium Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | package org.chromium.content.browser.test; |
| 6 | |
| 7 | import android.os.Handler; |
| 8 | import android.os.Looper; |
| 9 | import android.os.Message; |
| 10 | import android.os.MessageQueue; |
| 11 | import android.util.Log; |
| 12 | |
| 13 | import org.chromium.base.CalledByNative; |
| 14 | import org.chromium.base.JNINamespace; |
| 15 | import java.lang.reflect.Method; |
| 16 | import java.lang.reflect.Field; |
| 17 | import java.lang.reflect.InvocationTargetException; |
| 18 | |
| 19 | /** |
| 20 | * Handles processing messages in nested run loops. |
| 21 | * |
| 22 | * Android does not support nested message loops by default. While running |
| 23 | * in nested mode, we use reflection to retreive messages from the MessageQueue |
| 24 | * and dispatch them. |
| 25 | */ |
| 26 | @JNINamespace("content") |
| 27 | class NestedSystemMessageHandler { |
| 28 | // See org.chromium.base.SystemMessageHandler for more message ids. |
| 29 | // The id here should not conflict with the ones in SystemMessageHandler. |
| 30 | private static final int QUIT_MESSAGE = 10; |
| 31 | private static final Handler mHandler = new Handler(); |
| 32 | |
| 33 | private NestedSystemMessageHandler() { |
| 34 | } |
| 35 | |
| 36 | /** |
| 37 | * Processes messages from the current MessageQueue till the queue becomes idle. |
| 38 | */ |
| 39 | @SuppressWarnings("unused") |
| 40 | @CalledByNative |
| 41 | private boolean runNestedLoopTillIdle() { |
| 42 | boolean quitLoop = false; |
| 43 | |
| 44 | MessageQueue queue = Looper.myQueue(); |
| 45 | queue.addIdleHandler(new MessageQueue.IdleHandler() { |
| 46 | @Override |
| 47 | public boolean queueIdle() { |
| 48 | mHandler.sendMessage(mHandler.obtainMessage(QUIT_MESSAGE)); |
| 49 | return false; |
| 50 | } |
| 51 | }); |
| 52 | |
| 53 | Class<?> messageQueueClazz = queue.getClass(); |
| 54 | Method nextMethod = null; |
| 55 | try { |
| 56 | nextMethod = messageQueueClazz.getDeclaredMethod("next"); |
| 57 | } catch (SecurityException e) { |
| 58 | e.printStackTrace(); |
| 59 | return false; |
| 60 | } catch (NoSuchMethodException e) { |
| 61 | e.printStackTrace(); |
| 62 | return false; |
| 63 | } |
| 64 | nextMethod.setAccessible(true); |
| 65 | |
| 66 | while (!quitLoop) { |
| 67 | Message msg = null; |
| 68 | try { |
| 69 | msg = (Message)nextMethod.invoke(queue); |
| 70 | } catch (IllegalArgumentException e) { |
| 71 | e.printStackTrace(); |
| 72 | return false; |
| 73 | } catch (IllegalAccessException e) { |
| 74 | e.printStackTrace(); |
| 75 | return false; |
| 76 | } catch (InvocationTargetException e) { |
| 77 | e.printStackTrace(); |
| 78 | return false; |
| 79 | } |
| 80 | |
| 81 | if (msg != null) { |
| 82 | if (msg.what == QUIT_MESSAGE) { |
| 83 | quitLoop = true; |
| 84 | } |
| 85 | Class messageClazz = msg.getClass(); |
| 86 | Field targetFiled = null; |
| 87 | try { |
| 88 | targetFiled = messageClazz.getDeclaredField("target"); |
| 89 | } catch (SecurityException e) { |
| 90 | e.printStackTrace(); |
| 91 | return false; |
| 92 | } catch (NoSuchFieldException e) { |
| 93 | e.printStackTrace(); |
| 94 | return false; |
| 95 | } |
| 96 | targetFiled.setAccessible(true); |
| 97 | |
| 98 | Handler target = null; |
| 99 | try { |
| 100 | target = (Handler) targetFiled.get(msg); |
| 101 | } catch (IllegalArgumentException e) { |
| 102 | e.printStackTrace(); |
| 103 | return false; |
| 104 | } catch (IllegalAccessException e) { |
| 105 | e.printStackTrace(); |
| 106 | return false; |
| 107 | } |
| 108 | |
| 109 | if (target == null) { |
| 110 | // No target is a magic identifier for the quit message. |
| 111 | quitLoop = true; |
| 112 | } |
| 113 | |
| 114 | target.dispatchMessage(msg); |
| 115 | msg.recycle(); |
| 116 | } else { |
| 117 | quitLoop = true; |
| 118 | } |
| 119 | } |
| 120 | return true; |
| 121 | } |
| 122 | |
| 123 | @SuppressWarnings("unused") |
| 124 | @CalledByNative |
| 125 | private static NestedSystemMessageHandler create() { |
| 126 | return new NestedSystemMessageHandler(); |
| 127 | } |
| 128 | } |